In recent buildings, a sub-floor material is laid on a floor base such as a concrete floor slab by the intermediary of a leg member. Then, a floor finishing material is adhesively integrated with the sub-floor material by the intermediary of an adhesive to form a floor structure. The use of the floor finishing material having a wood grain pattern or the like improves the appearance and design features of the floor.
As an adhesive used for a floor structure, an epoxy-based adhesive or a urethane-based adhesive is used. However, in a floor structure formed with the epoxy-based adhesive or the urethane-based adhesive, a cured coating film of the adhesive is hard. Therefore, there has been a problem that the floor finishing material squeaks when a person walks on the floor finishing material. Such a problem is called a “floor squeak” or the like.
In order to inhibit the floor squeak, a floor structure formed with a modified silicone-based adhesive is known (Patent Literature 1). However, in the floor structure formed with a modified silicone-based adhesive, a cured coating film of the modified silicone-based adhesive is soft. Therefore, there has been a problem that the occurrence of shrinkage of the floor finishing material caused by temperature changes in the ambient environment causes a gap to be generated between adjacent floor finishing materials. Such a problem is called a “joint gap” or the like.
Also, when scratches are formed on the floor finishing material, the floor finishing material with scratches is peeled off from the sub-floor material, and a new floor finishing material is bonded to the sub-floor material. By replacing the floor finishing material in this manner, the floor finishing material is repaired. However, when conventional adhesives such as the epoxy-based adhesive, urethane-based adhesive, and modified silicone-based adhesive are used, the floor finishing material was firmly bonded to the sub-floor material by the intermediary of the adhesives. Accordingly, in some cases, the floor finishing material was inhibited from being easily peeled off from the sub-floor material. In such a case, an attempt to forcibly peel off the floor finishing material from the sub-floor material causes part of the sub-floor material to be peeled off together with the floor finishing material to damage the sub-floor material. Therefore, there has also been a problem that it is difficult to peel off only the floor finishing material for replacement.